reCAPTCHA is a free captcha service provided by Google. It is designed to be easy for humans and difficult for bots.

To use this package you must have a Google account and sign up for the reCAPTCHA API. After installing the package go to System & Settings -> Permissions & Access -> Captcha Setup in the Dashboard, select reCAPTCHA as the active captcha provider and provide your site and secret keys obtained from Google.